Most shoes, including athletic shoes, are designed so that the medial side and the lateral side of the shoe are symmetric. However, the anatomy of the foot is not symmetric between the medial and lateral sides. While a symmetric shoe may be more aesthetically pleasing than an asymmetric shoe, it does not properly fit the foot, resticts the natural movement of the foot, and decreases foot stability.
Some asymmetric features have been incorporated into prior art shoes. For example, shoes are often designed with an anatomical arch, a natural lateral curvature in lasts and a natural toe curvature in lasts. However, several areas of misalignment are still found in many current shoes wherein the symmetry of the portions of the shoe detract from its comfort and proper functioning, particularly when the shoe is an athletic shoe. For example, the symmetric placement of stability straps and flex notches in the forepart hinders movement of the lateral metatarsal-phalanges joint. While the medial flex notch and stability strap are respectively aligned directly over and posterior to the medial metatarsal-phalanges joint, the symmetric placement of the lateral flex notch and stability strap locates them respectively anterior and directly over the lateral metatarsal-phalanges joint, causing this hinderance. The generally symmetric placement of the quarter heights and quarter notches in current shoes also fails to contour the upper to the differences between the medial and lateral malleolar height and length. Finally, when the anterior edge of the midsole wedge and the board in a combination lasted shoe extends transversely from posterior of the first metatarsal-phalanges joint to directly under the fourth and fifth metatarsal-phalanges joints, natural foot flexure is inhibited, forefoot valgus is caused and stability may decrease.